In the context of the conditioning of histological samples, in particular in the preparation of histological samples in the context of an embedding process for later microtoming, they are firstly fixed by the application of various chemicals. The tissue liquid originally present in the natural cavities of the sample is thereby replaced, in multiple steps, by a fixing liquid, for example by formalin. In order to convert the fixed samples into a state that permits sectioning by means of a microtome, the fixing liquid is replaced by an embedding medium, for example paraffin, gelatin, agar, nitrocellulose, polyester wax, polyethylene glycol, or plastic. During the aforementioned processes, the samples are usually located in a cassette that comprises a plurality of sieve-like openings so that the chemicals can flow around the samples. A particular embodiment of such a cassette is known, for example, from DE 43 33 118 A1.
After infiltration of the embedding medium into the samples, the excess paraffin is drained off. After this step, the samples can be located anywhere within the cassette; because of the paraffin residues adhering to them, the samples as a rule adhere to the cassette cover, in the cassette cavity, and/or to one another. Stuck-together clumps of samples often form within the cassette.
Before further processing, in particular before automated, machine-controlled further processing, of the sample, for example before the further step of casting the samples into a paraffin block (called “blocking”), the sample or samples must be present in isolated fashion. Detachment and isolation can be performed, for example, using tweezers; disadvantageously, the risk exists that a sample may be damaged in this context and possibly even become unusable. In particular, the risk exists that changes which result in artifacts upon later analysis of tissue sections of the sample may be inadvertently caused to a sample.
DE 10 2007 022 014 A1 discloses a tissue embedding apparatus and a method for operating the same, which apparatus comprises a manipulation unit with which a sample inside the opened cassette can be transferred into a predefined position, orientation, and/or storage area.
EP 2 184 598 A1 discloses an apparatus for treating a tissue sample that comprises a bath for melted paraffin. An ultrasonic vibrator is provided for heating the bath.
DE 40 19 182 A1 discloses a method for impregnating tissue samples in paraffin. The method is notable for the fact that soaking of the tissue sample occurs in a closed, evacuated working space with ultrasound acting on the tissue sample and on the liquid paraffin surrounding said tissue sample. A similar method is known from US 2010/0144002 A1. According to this method, provision is made to apply infrasound or alternatively ultrasound in order to accelerate an infiltration process.
U.S. Pat. No. 6,207,408 B1 discloses a method for histological sample processing in which the sample is heated with the aid of microwaves during fixing, dehydration, and fat elimination.
US 2010/0151513 A1 discloses an apparatus and a method for sample handling and for embedding. According to the method, provision is made firstly to position a plurality of sample receptacles in an introduction apparatus, each sample receptacle having a mold associated with it; and then to convey the introduction apparatus into a wax bath. The introduction apparatus is then removed again from the wax bath and transferred to a cooling station in order to evaluate the wax.
It has become apparent that occasionally, despite every precaution, damage occurs to the sample or samples located in the cassette. The damage is usually manifested by the fact that the sample is torn or even ripped apart.